Geological Note: The Tamar fracture system in Tasmania: Does it exist?

Simultaneous inversion of active and passive source datasets for 3‐D seismic structure with application to Tasmania

“…Interestingly, the so‐called Tamar Fracture System or TFS (approximately coincident with the Tamar River in Figure 3), which has traditionally been used to mark the boundary between the Eastern and Western Tasmania Terranes, does not overly the velocity or interface depth variation (Figure 3d). This corroborates the view of Leaman [1994] that the TFS is a shallow feature unrelated to the terrane boundary at depth.…”

“…Although there is no general agreement as to the tectonic assemblage of western Tasmania [ Rawlinson et al , 2006], there is little doubt that it largely occurred during the Middle to Late Cambrian Tyennan Orogeny. Eastern Tasmania contains no evidence of the Tyennan Orogeny or Proterozoic outcrop, and there has been much debate about the nature of the transition between the two terranes [ Elliot et al , 1991; Leaman , 1994]. Seismic tomography is therefore well placed to contribute towards an improved understanding of Tasmanian geology and tectonic history.…”

The significance of a new locality for Monograptus thomasi (Early Devonian) southwest of Beaconsfield, Tasmania, and of the Corn Hill Formation

“…The germ of one solution to the anomaly of the position of the Corn Hill Formation emerged first in 1973 (before the Formation had been recognised), when a geophysical anomaly in the Dazzler Range west of Beaconsfield was attributed to thrusting (Leaman et aL 1973). A little later, Gee & Legge (1979: 29, fig.…”

“…Several of the authors in the Geophysics chapter (13) Richardson (p.466), and some problems were noted. The existence of the Fracture System (Leaman 1994) and its position, i.e. the boundary between the Eastern and the Western Terrane, have been debated (Elliott etaL 1993, Leaman 1994, Hills 1998.…”

“…The existence of the Fracture System (Leaman 1994) and its position, i.e. the boundary between the Eastern and the Western Terrane, have been debated (Elliott etaL 1993, Leaman 1994, Hills 1998. The present conundrum is the recognition of the Corn Hill Formation, correlated with the Mathinna Supergroup, part of the Eastern Tasmania Terrane, lying not only west of the Tamar River, but also west of outcrops ofWurawina Supergroup rocks, Denison and Gordon Groups, characteristic of the Western Tasmania Terrane.…”